Purchasing a new set of golf clubs is a major investment for many golfers. Therefore, any golfer who is about to invest in purchasing a new set of clubs typically takes the extra step to insure that their new golf clubs are custom fit rather than purchasing “off-the shelf golf clubs.” “Off-the-shelf” golf clubs are one-size-fits-all, designed for a “typical” golfer. Normally an “average golfer” refers to someone who is approximately 5-foot-9 or 5-10 and hits a 5- or 6-iron about 160 yards. However, every golfer has a different body shape, and a different golf swing. A golfer might get lucky with an off-the-shelf set, but many golfers will find that such a set is ill-suited for their particular body and/or swing. As a result many golfers are opting for custom fitting session to insure that they are receiving the greatest payback for their new investment.
A typical club fitting session begins with a static fitting. That is, various measurements of the golfer, such as the golfer's height, the distance between the golfer's fingertip and floor, the golfer's hand size, and the like are measured and recorded. Using these measurements, the club fitter can determine a set of specifications for a custom fit golf club, as a starting point. Once the static fitting is complete, the club fitting session moves to a dynamic fitting, in which the golfer hits numerous balls so that the ball flight can be observed and the specifications of the custom-fit golf club can be refined. Typically, the golfer will hit many variations of the same club. For instance, a well-equipped fitting center might have dozens of a particular club, say a 6-iron. Each of the 6-irons will be different from the next in some way, such as lie angle, shaft flex, shaft length, and the like. The main purpose is to find the best combination of shaft, lie, grip, and swing weight that produces the best ball flight for that particular golfer.
During the dynamic fitting process, one specification that is checked and refined is the lie angle of the golf club. To determine the proper lie angle, the golfer is asked to hit several balls of a hard surface, such as a lie board. By making contact with the lie board, an impact mark will be left on the sole of the golf club, which helps determine the proper lie angle. For example, if the impact mark is near the center of the sole as measured from the heel to the toe, the lie angle is correct for that particular golfer. However, if the impact mark is toward the toe of the golf club, this indicates that the lie angle is too flat for the particular golfer. Similarly, if the impact mark is toward the heel of the golf club, the lie angle is too upright for the particular golfer. By observing where the impact marks on the sole of the golf club occur, the club fitter can determine the optimal lie angle of the golf club for that golfer.
However, determining the proper lie angle required that the club fitter make an intelligent guess as to how far the impact mark was from the center of the sole of the golf club and therefore the approximate lie angle. Once the approximate lie angle is determined, the golfer must hit several more balls with a golf club with a modified lie angle. This process is repeated until the proper lie angle is determined. To reduce the “guesswork” of the club fitter for selecting the proper lie angle, trial golf clubs used for club fitting may contain graduated markings along the sole that run perpendicular to the face of the golf club. Each graduated marking corresponds to a particular incremental change in the lie angle referenced from the center of the sole. Therefore, the club fitter can easily tell the proper lie angle for a particular golfer by observing at which graduated mark the impact mark appears, thereby eliminating any guesswork from determining the proper lie angle.
Another specification that is refined during the dynamic club fitting session is the loft angle of the golf club. Normally, this characteristic is determined using subjective criteria. In a typically club fitting session, the golfer will hit several shots with a golf club having a known loft angle. The club fitter observes the flight path of the golf ball and determines whether in his or her judgment, the flight of the ball is too high or too low. If the club fitter believes that the ball flight is too high, he or she will have the golfer hit several more shots with a golf club that has a stronger (less) loft. Conversely, if the club fitter believes that the ball flight is too low, he or she will have the golfer hit several more shots with a golf club that has a weaker (more) loft. This process continues until, in the view of the club fitter, that the golfer has achieved the proper ball flight.
After a club fitter has gathered the necessary data regarding the lie angle and loft angle necessary for the different clubs of a particular golfer, it is often desired to custom modify one or more of a golfer's clubs to provide the desired loft angle and lie angle for a particular club. Conventional devices are available to the professional club fitter that enable the club fitter to individually adjust the lie angle and/or loft angle for certain types of golf clubs. For example, U.S. Pat. No. 6,871,414 to Burner et al. (“'414 Patent”) discloses an apparatus for measuring and adjusting golf club loft and lie. The apparatus is a large mechanical structure that includes a clamping assembly to hold a golf club, two infrared shaft cameras to provide a stereoscopic view of the club shaft, stall sensors, constraint blocks, a clamp inclinometer and a structure inclinometer to measure orientation relative to gravity, and a computer system including a monitor to provide a graphical user interface. The '414 Patent discloses that the apparatus can be used by a professional technician to measure the lie and loft angles of a particular golf club and implement a bending force on the clamping assembly to adjust the lie and loft angles of the club.
U.S. Pat. No. 5,421,098 to Muldoon (“'098 Patent”) discloses a machine for adjusting loft and lie angles of a golf club head. The apparatus disclosed in the '098 Patent provides three components: (1) a fitting gauge attachable to a golf shaft to identify the lie angle and loft angle for a golf club, (2) a bench with components for attaching a golf club head, and (3) an adjusting tool fixed to the bench that enables the shaft of the club to be manipulated relative to the golf club head. The bench assembly of the '098 Patent apparatus provides a loft gauge and a lie gauge that indicate to a technician using the apparatus the current angles of the golf club head. Therefore, the technician can manipulate the adjusting tool until the desired loft and lie angles are achieved.
U.S. Patent Publication No. 2007/022799 to Latiri (“'799 Publication) describes a golf club hosel bending fixture. The bending fixture of the '799 Publication provides an angularly articulating crown jaw assembly, a relatively fixed lower jaw assembly generally opposite the crown jaw, a longitudinally disposed back jaw assembly, and a club head face jaw disposed at the base of the crown jaw track. The four jaw assemblies serve to clamp a golf club head securely in place. Thereby the golf club head can be manipulated by the articulating assemblies to adjust the lie angle and loft angle of the golf club head.
Despite working for their intended purposes, these conventional golf club head bending machines are unable to accurately and effectively modify wood-type golf club heads. More particularly, if the conventional iron golf club head bending machine described in the '799 Publication is used to adjust the lie or loft angle of a wood-type golf club head, the club head with be damaged and/or the performance of the club head will be degraded. Therefore, there is a continuing need for a wood-type golf club head enabled to be adjusted by a conventional iron golf club head bending machine. Furthermore, there is a need for a wood-type golf club head with improved playing performance that is enabled to be adjusted by a conventional iron golf club head bending machine.